What causes "No signatures for nil Envelope" in hyperledger/fabric?

Guard with a nil check on the envelope before calling EnvelopeAsSignedData and reject the request early.

No signatures for nil Envelope

Error message

No signatures for nil Envelope

What it means

EnvelopeAsSignedData extracts the signature data from a common.Envelope: it unmarshals the payload and pairs env.Payload with env.Signature and the creator from the SignatureHeader. A nil Envelope has no signature to extract, so this error is returned immediately.

Source

Thrown at protoutil/signeddata.go:63

			return nil, err
		}

		result[i] = &SignedData{
			Data:      bytes.Join([][]byte{configSig.SignatureHeader, ce.ConfigUpdate}, nil),
			Identity:  sigHeader.Creator,
			Signature: configSig.Signature,
		}

	}

	return result, nil
}

// EnvelopeAsSignedData returns the signatures for the Envelope as SignedData
// slice of length 1 or an error indicating why this was not possible.
func EnvelopeAsSignedData(env *common.Envelope) ([]*SignedData, error) {
	if env == nil {
		return nil, errors.New("No signatures for nil Envelope")
	}

	payload := &common.Payload{}
	err := proto.Unmarshal(env.Payload, payload)
	if err != nil {
		return nil, err
	}

	if payload.Header == nil /* || payload.Header.SignatureHeader == nil */ {
		return nil, errors.New("Missing Header")
	}

	shdr := &common.SignatureHeader{}
	err = proto.Unmarshal(payload.Header.SignatureHeader, shdr)
	if err != nil {
		return nil, fmt.Errorf("GetSignatureHeaderFromBytes failed, err %s", err)
	}

View on GitHub (pinned to 2736b63f8f)

Solutions

Guard with a nil check on the envelope before calling EnvelopeAsSignedData and reject the request early.
Ensure GetEnvelopeFromBlock / proto unmarshaling errors are handled so nil envelopes never reach ACL checks.
When building envelopes programmatically, marshal a valid Payload into env.Payload before submission.
In tests, use a minimal valid envelope rather than nil to exercise the intended path.

Example fix

// before
sd, err := protoutil.EnvelopeAsSignedData(env)

// after
if env == nil {
    return status.Error(codes.InvalidArgument, "envelope is nil")
}
sd, err := protoutil.EnvelopeAsSignedData(env)

Defensive patterns

Strategy: type-guard

Validate before calling

if env == nil || len(env.Payload) == 0 {
    return errors.New("envelope with payload required")
}

Type guard

func validEnvelope(env *common.Envelope) bool {
    return env != nil && len(env.Payload) > 0
}

Try / catch

sd, err := protoutil.EnvelopeAsSignedData(env)
if err != nil {
    return fmt.Errorf("cannot check ACL: %w", err)
}

Prevention

Ensure GetEnvelopeFromBlock errors are propagated, not swallowed into a nil envelope.
Nil-check envelopes before ACL checks (CheckACL / NewSessionAC).
Build envelopes with protoutil helpers so Payload is always marshaled.
In deliver/eval paths, reject envelopes with empty payload bytes early.

When it happens

Trigger: Calling EnvelopeAsSignedData(nil) — e.g. CheckACL / CheckACLNoChannel or NewSessionAC receiving a nil envelope because a prior GetEnvelopeFromBlock / Unmarshal step failed or returned nil without propagating an error.

Common situations: ACL resource provider invoked with an envelope extracted from a malformed block; deliver sessions created with a nil envelope; tests exercising the nil case; transaction filters dropping payloads upstream leaving nil envelopes.

Related errors

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/da11296c31c70701. Report an issue: GitHub.